It is mainly the difference in frequency and waveform that determines the difference in working principle and effect.
First of all, the production frequency of RF-grade high-frequency electrosurgery is between 1.71~4.0 MHz, while the common frequency of ordinary high-frequency electrosurgery is 450 kHz~650 kHz.
Secondly, they work differently.
In the same circuit, the current through a conductor is proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor. This is Ohm's law. When electrical current passes through human tissue, these tissues generate heat due to their own impedance.
When the ordinary high-frequency electrosurgical knife works, the current passes through the electrodes. The smaller the contact area between the electrode and the human body, the greater the impedance, and the greater the heat of the contact part, and the cells are heated, ruptured and coagulated. (Similar to balloon burns) for cutting or hemostasis purposes.
The working principle of the RF high-frequency electrosurgical knife is to output 1.71MHz/4.0 MHz RF electromagnetic waves at the working end of the electrode, so that a large number of polar water molecules affected by the electromagnetic field rapidly oscillate and impact under the action of the high-frequency electromagnetic field, causing the cell wall to rupture. achieve the purpose of cutting. At the same time, the friction of water molecules generates heat during high-speed motion, converts electrical energy into heat energy, increases body temperature, converts plasma soluble protein into insoluble protein monomer, thrombin converts protein monomer into protein polymer, and protein polymer interacts with each other The interweaving forms a clot, completing the clotting process.
The last, the difference in working principle determines the difference in working method and effect.
In the operation of ordinary high-frequency electrosurgery, a negative plate (current flows through the human body, and then flows back from the negative plate to the host to form a loop), the area is large enough, and the contact with the human body is good, otherwise, the temperature is high, and a certain amount of Mechanical force, the wound surface will be easy to be caused larger, and the wound healing time is long.
RF high-frequency electrosurgery does not require current or negative film. It only needs to form electromagnetic waves between the neutral plate and the electrode. It does not need to be in direct contact with the human body.